The present invention relates to a vehicular rotational apparatus that has a rotary body and an electric motor. The rotary body is operably connected to a rotary shaft, which drives a mechanism, and transmits power to the rotary shaft from an external drive source. The electric motor selectively drives the rotary shaft.
A typical compressor drives a compressing mechanism for compressing refrigerant by selectively using power from an external drive source and power from an electric motor, which is located on the compressor. Japanese Laid-Open Patent Publication No. 11-30182 discloses such compressor.
The compressor of the above publication has a pulley for receiving power from the external drive source and a rotary shaft for driving the compression mechanism. A pulley one-way clutch is located in a power transmission path between the pulley and the rotary shaft. A motor one-way clutch is located in a power transmission path between the electric motor for driving the compression mechanism and the rotary shaft.
Therefore, the compression mechanism is driven by power from the external drive force without rotating the rotor of the electric motor. As a result, power transmitted from the external drive source to the rotary shaft is prevented from being consumed unnecessarily for purposes other than driving compression mechanism.
In the above structure, the size of the compressor is reduced by using the one-way clutch instead of an electromagnetic clutch. However, the location of, for example, the electric motor to reduce the size of the compressor is not disclosed.
Accordingly, it is an objective of the present invention to provide a vehicular rotational apparatus that is minimized in the axial direction of a rotary shaft.
To achieve the above objective, the present invention provides a vehicular rotational apparatus that is driven by an external drive source. The rotational apparatus includes a housing, a rotary shaft, a first rotary body, an electric motor, a first clutch mechanism, and a second clutch mechanism. The rotary shaft is rotatably supported by the housing. The first rotary body is operably connected to the rotary shaft and includes a power transmission portion. When power is transmitted from the external drive source to the power transmission portion, the first rotary body is rotated. The electric motor rotates the rotary shaft and includes a second rotary body, which is operably connected to the rotary shaft. At least part of the electric motor overlaps the power transmission portion in the axial direction of the rotary shaft. The first clutch mechanism is located between the first rotary body and the rotary shaft and selectively permits and prevents power transmission between the first rotary body and the rotary shaft. The second clutch mechanism is located between the second rotary body and the rotary shaft and selectively permits and prevents power transmission between the second rotary body and the rotary shaft.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.